Improvement in pumps



UNITED STATES PATENT OFFICE.

AZEL s. LYMAN, OF NEW YORK, N. Y.

IMPROVEMENT IN PUMPS.

Specification forming part of Letters Patent No. 187.153, dated February6, 1877 application filed February 17, 1876.

To all whom it may concern:

Be it known that I, A. S. LYMAN, of the city, county, and State of NewYork, have invented certain Improvements in Balanced Screw-Pumps, ofwhich the following is a specification The principal objections to theordinary screw-pump, when driven by the'ordinary engine, are, first, thereaction of the shaft carrying the screw is very great upon its base,being at all times equal to the whole amount lifted by the screws;second, the required velocity of revolution is so great, that much poweris lost in gearing up from the comhead to its upper end, surrounded by acylinder strongly supported, and forcing water under this piston, so asto lift the shaft from its base, and cause it to ride on thewaterbearing at the top.

My first and principal improvement consists in balancing the screw-pumpby'using right and left screws on the same shaft, so that as they forcethe water in opposite directions, they balance each other; second, indispensing with the gearing ordinarily used for the high velocity byattaching it to the reacting vacuumrotary engine direct by a mere clutchor other suitable arrangement, thus also obtaining a much highervelocity, and setting the screws at a much lower pitch, by which muchmore of the power is utilized in forcing the water directly forward.

Figure 1 is a vertical central section. Fig. 2 is a horizontal sectionthrough a: a; of Fig. 1. Fig. 3 is a horizontal section through y y ofFig. 1.

B B B represent the upper set of screws, which are fixed upontherevolving shaft S S, so as to force the water downward. O O

0 represent the lower set of screws, which enough greater than theupward to balance the weight of the shaft and other revolving parts.

Either or both modes may be used in practice; but I prefer making themlarger in area with the same pitch.

On the top of the shaft S S I attach a clutch, (not shown,) whichcouples it directly to the shaft of my vacuum rotary engine.

As that engine will make six thousand revolutions per minute, more orless, as its reacting surfaces describe a circle less or greater thanabout four feet in diameter, it will drive this pump with any requirednumber of revolutions per minute without any gearing for increasing itsspeed.

The course of the water is shown by the arrows.

The water to supply the lower screws 0 O O enters by the lower openingsR R, and is forced upward by these screws past the guides D D, whichprevent it from attaining a rotary motion round the shaft, thence outthe side openings E E, and up the passage N N.

The water to supply the upper screws B B B enters at the bottom, passesup the passage I I, and across the large ascending passage N N, by thelong narrow passages P P, and is forced down by the screws past theguides L L, and out the large openings E E E, whence, together with thewater from the lower screws, it is forced up the large passage N N.

I claim as my invention 1. A screw-pump, having its shaft provided withright-and-left hand screws, in

combination with the conduits, so arranged that the screws, revolving inthe same direction, force the water toward each other, balancing thescrews substantially as speci- 2. A screw-pump, having the screwthatforces the water downward. either larger in area, or of greater pitchthan the screw that forces the water upward, thus supporting the movingparts on the water, substantially as specified.

3. A screw-pump, in which the water, or a large portion of .it, is sentabove the upper screw in a conduit outside that in whichthe screwrevolves, substantially as specified.

- AZEL S. LYMAN.

W'itnesses:

'W. L. BENNEM,

JAS. S. WIGHTMA'N.

